As with all technologies, the art of plumbing continues to evolve, and with it the tools for effecting it. Currently popular is the use of non-metallic tubing to supplant copper tubing and formerly cast iron pipe in distributing hot, cold and potable water throughout a building. Where iron pipe was threaded and copper pipe was soldered, the polymers used in non-metallic tubing lend themselves well to neither of these connection methods.
Consequently, clamps or compression fittings which can be effected at room temperature are used most commonly to join non-metallic tubing. One such technique, used with plastic tubing, particularly PEX tubing, is to compress or crimp a malleable band around the tubing to create a leak-proof joint. When it was a comparatively new and initially unproven technology, the use of PEX tubing called for new tools and new testing standards before its crimped connections could become trusted and widely used.
These tools are today widely known in the prior art, some of which is discussed below, but all share in common one principle of operation: they all work to compress the malleable band uniformly around its entire circumference. Consequently, they all, in essence, comprise a pair of limber C-shaped crimping sections built uniquely for one single size of tubing. Some comprise more than just two crimping sections, linked together as a chain around the joint to be crimped. They act in concert with a separate power tool or a specialized pliers-like actuator which closes the C-shaped sections around the band and then, by tensile stresses in the sections, compress the band inward. Many elaborations on this theme have evolved, to guarantee precise, proper and complete compression and to afford different actuation mechanisms. A consequence of all this development has been that the available tooling is both cumbersome and expensive.
U.S. Pat. No. 6,923,037 to Bowles et al., and U.S. Pat. No. 6,477,757 to Viegener disclose details of the complexity of typical actuators. U.S. Pat. No. 6,044,681 to Frenken illustrates a three-segment crimping tool, while U.S. Pat. No. 5,697,135 to Dischler is exemplary of a 5-segment tool. Recently granted U.S. Pat. No. 7,059,166 to Bowles et al. reinforces the currency and commonplace use of C-shaped crimping sections and the delicate, complex measures which are needed in properly closing their sections to effect an adequately crimped connection.